CSB Issues Safety Alert Regarding Emergency Pressure Relief Systems
The Chemical Safety Board (CSB) has issued a safety alert regarding emergency pressure relief systems as the agency is continuing to see them playing th...
The Chemical Safety Board (CSB) has issued a safety alert regarding emergency pressure relief systems as the agency is continuing to see them playing their part in major chemical incidents.
⚡ TL;DR: CSB investigations found that emergency pressure relief systems often discharge toxic or flammable materials unsafely into the atmosphere or back into plants. CSB recommends following API 521 best practice guidance and directing discharge to flare or scrubber systems rather than venting directly to atmosphere. Proper design prevents catastrophic releases and worker/public exposure.
Who is the CSB?
The CSB is an independent federal agency who investigates the root causes of chemical incidents at industrial sites such as chemical plants, refineries, and manufacturing facilities. They are not a regulatory agency, but their teams of investigators make recommendations to OSHA and EPA, industry groups and the facilities they investigate.
Emergency Pressure Relief System Issues
In its investigations, CSB is continuing to find issues with the safety of emergency pressure relief systems. In several of their investigations these systems were found to be discharging toxic or flammable materials to areas which were not safe for workers or the public. Emergency pressure relief systems are devices installed on storage tanks, silos, vessels and processing plant equipment to help relieve the excessive pressure caused by fire, process failure, equipment failure or some other change in condition.
⚠️ What’s at stake: Chemical release incidents from poorly designed pressure relief systems have resulted in OSHA fines exceeding $100,000, EPA environmental citations with penalties up to $50,000 per day, worker injury claims exceeding $1 million, and major incident investigations that disrupt operations for months.
Three Key CSB Suggestions
CSB recommends that rather than discharge into the air or back into the plant, emergency relief systems should discharge to a flare or a scrubber system. CSB offers three key lessons: Follow Existing Good Practice Guidance using API 521; Evaluate Whether the Atmosphere is the Appropriate Discharge Location or if There May Be Safer Alternatives; and Ensure Hazardous Chemicals Vented Into the Atmosphere Discharge to a Safe Location.
Does your facility have emergency pressure relief systems? Are they designed per API 521? Are discharge locations away from worker areas and the public? iSi Environmental can audit your relief system design against CSB recommendations and current engineering standards. Schedule a pressure relief system audit →
💰 The cost of non-compliance: Chemical releases from improperly designed relief systems have triggered environmental cleanup costs exceeding $500,000, OSHA fines of $50,000–$150,000, and operational shutdowns costing facilities $100,000+ per day during investigations and repairs. CSB-recommended violations are treated seriously by EPA and OSHA.
Frequently Asked Questions
Q: What is the Chemical Safety Board (CSB) and what is its role in workplace safety?
The Chemical Safety Board is an independent federal agency that investigates the root causes of chemical incidents at industrial facilities including chemical plants, refineries, and manufacturing facilities. The CSB is not a regulatory agency but makes recommendations to OSHA, EPA, industry groups, and investigated facilities based on investigation findings. CSB recommendations carry significant weight with OSHA and EPA and are often incorporated into regulatory guidance. iSi Environmental monitors CSB recommendations and helps facilities implement recommended safety improvements.
Q: What are the safety concerns with emergency pressure relief systems?
CSB investigations have found that emergency pressure relief systems often discharge toxic or flammable materials directly into the atmosphere or back into the plant, creating hazards to workers and the public. Emergency relief systems are installed on storage tanks, silos, vessels, and equipment to release pressure from fire, process failure, equipment malfunction, or operational changes. If discharge locations are unsafe or uncontrolled, the released materials can cause exposure, combustion, or environmental contamination. Facilities must ensure relief systems discharge to safe locations.
Q: What does API 521 guidance recommend for emergency pressure relief system design?
API 521 (American Petroleum Institute) provides industry best practice guidance for pressure-relieving systems. CSB recommends facilities follow API 521 guidance when designing or evaluating emergency relief systems. Key recommendations include directing discharge to flare systems or scrubber systems rather than venting directly to the atmosphere. Flare systems safely combust flammable vapors, while scrubber systems capture and neutralize hazardous chemicals. Discharge locations must be away from worker areas and the public. iSi Environmental helps refineries, chemical plants, and manufacturing facilities in Oklahoma and Kansas evaluate emergency relief system safety.
Q: What alternatives exist to atmospheric discharge for emergency relief systems?
CSB recommends flare systems and scrubber systems as safer alternatives to atmospheric discharge. Flare systems combust flammable vapors safely at elevated heights away from worker and public areas. Scrubber systems capture gaseous or vapor hazardous materials and remove them chemically before atmospheric release. Other alternatives may include enclosed blowdown systems or collection tanks. The appropriate technology depends on the specific chemicals, process hazards, and facility layout. Facilities should consult with engineering experts and follow API guidance. iSi Environmental can assess relief system designs for compliance with CSB recommendations.
Every satisfactory pressure relief system starts with proper design and verification. iSi Environmental helps refineries, chemical plants, and manufacturing facilities in Kansas and Oklahoma audit emergency relief systems against API 521 and CSB recommendations. Schedule pressure relief system review →
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